下面的SQL语句怎么写？

if()--这里判断A表中Code字段中的记录是否包含字符串USD？是在中间还是末尾？？该怎么写
begin
select UserInfoId,Code,TradeCount,Code,
(isnull((select top 1 Price from hangqing.dbo.WH_Ticks where substring(StockSymbol,3,len(StockSymbol)-2)=A.Code order by [Time] desc),0) as nowPrice-CBPrice) * TradeType*10000*TradeCount/nowPrice AS FloatYingKui
from Moni_Exchange A 
where UserInfoId=@userid
end

else
begin
select UserInfoId,Code,TradeCount,Code,
(isnull((select top 1 Price from hangqing.dbo.WH_Ticks where substring(StockSymbol,3,len(StockSymbol)-2)=A.Code order by [Time] desc),0)-CBPrice) * TradeType*10000*TradeCount AS FloatYingKui
from Moni_Exchange A 
where UserInfoId=@userid
end

---

SQL code:
if exists(select 1 from a where code like '%_USD_%' ) --中间
if exists(select 1 from a where code like '%USD' )-- 末尾

---

SQL code:
if exists(select 1 from a where code like '%USD%' ) --中间
if exists(select 1 from a where code like '%USD' )-- 末尾

---

楼上的没明白我的意思

if(right(A.code,3)='USD')
begin
--单笔合约浮动盈亏（美元）2（间接标价货币：如欧元|美元 浮动盈亏=（最新平仓价-开仓价）×买卖方向参数×10000×手数
s